Children with autism have specific difficulty in the initiation of social communication behaviors, including looking at the faces of social partners. The Polyvagal theory proposes a social engagement system, including temporal lobe activity in the fusiform gyrus and superior temporal sulcus, vagal control of the heart, and facial motor control, that evolved to enable social engagement behavior in humans during states of calm and safety. Applying this theory to autism leads to predictions that elements of the social engagement system are compromised. This study will examine this hypothesis by measuring EEG temporal power, vagal tone, and eye movements while children with autism are viewing audiovisual images of their caregiver versus a stranger in simple and complex environments. It is hypothesized that, in contrast to controls, children with autism will show decreased EEG temporal activity, vagal control of the heart, and gazes to the eyes of their caregiver, especially the stimuli in complex environments, whereas controls will show increased activity of the social engagement system to their caregiver and will not be affected by complexity of the stimuli environment.